Generally, a wind turbine includes a rotor that includes a rotatable hub assembly having multiple blades. The blades transform wind energy into a mechanical rotational torque that in turn drives a drivetrain coupled to an electrical generator. However, electrical generators, motors and the drive train in a wind turbine may generate torsional and radial vibrations due to presence of defective components such as bearings, gears, or the like. Conventionally, vibration analysis of components in a wind turbine can be performed to monitor operating conditions. For example, mechanical faults in wind turbines having a drive train may generate vibrations at the rotor rotating frequency. However, it has been found that vibration signals may not detect all types of faults associated with the various components of the drive train.